Research Of Surface Roughness Measuring Bench

Surface roughness is an important indicator that is evaluation and reflection on the surface quality of various mechanical parts. Surface roughness not only affects the combination and sealing of parts,adhesive bonding strength among parts,corrosion resistance,the current flow on the surface of conductor,liquid and gas resistance,wearing resistance, but also affects the vibration and noise of mechanical equipment,assembly quality,power consumption and so on. At present, the evaluation of surface roughness is mainly two-dimensional and the measuring instrument is designed aiming at two-dimensional parameters, but the method of two-dimensional evaluation can not reflect the status of surface topography. In order to meet the tendency of detection on arbitrary pose surface roughness and three-dimensional surface detection, it is urgently to develop three-dimensional roughness measurement system.In view of the situation above, this paper developed multiple-degree surface roughness measuring bench based on Stewart platform. According to the requirement of measurement of surface roughness, the overall scheme is designed and the specific structure of bench is analyzed and designed. In order to get the satisfied structure, the key structural parts are optimized and simulated.According to the differential relationship of Stewart platform the forward kinematics error model for the pose error analysis of the end effectors has been formulated. The pose errors of the end effectors can be directly achieved when the structural parameters and errors are given. The mathematical model of multiple-degree surface roughness measuring bench is established. The mathematical simulation of roughness measurement about plane is studied by MATLAB software. Curve of length of each pole is obtained.The solid model of multiple-degree surface roughness measuring bench is established. It provides kinematical simulation of multiple-degree surface roughness measuring bench with a correct virtual prototype model. The kinematical simulation of pose adjustment and roughness measurement about plane and round face is accomplished by ADAMS. Simulation animation and curves are obtained. On one hand, the results show that virtual prototype model and mathematical model are corresponding and correct by comparing the kinematics simulation of virtual prototype with mathematical simulation, both models can be used for further simulation and research of bench. On the other hand, the simulation results show that no interference phenomenon occurred, the length change of each pole is within maximum change, the trip itinerary of moving platform meets the need of roughness measurement, the velocity and acceleration of each pole are within reasonable range, the entire performances of bench meet requirement of measurement.